movement: day one watch face, counts days from birth

movement/watch_faces/complications/day_one_face.h

@@ -0,0 +1,31 @@
+#ifndef DAY_ONE_FACE_H_
+#define DAY_ONE_FACE_H_
+
+#include "movement.h"
+
+// The Day One face is designed to count upwards from the wearer's date of birth. It also functions as an
+// interface for setting the birth date register, which other watch faces can use for various purposes.
+
+typedef struct {
+    uint8_t current_page;
+    uint16_t current_year;
+    uint16_t birth_year;
+    uint8_t birth_month;
+    uint8_t birth_day;
+    bool birthday_changed;
+} day_one_state_t;
+
+void day_one_face_setup(movement_settings_t *settings, void ** context_ptr);
+void day_one_face_activate(movement_settings_t *settings, void *context);
+bool day_one_face_loop(movement_event_t event, movement_settings_t *settings, void *context);
+void day_one_face_resign(movement_settings_t *settings, void *context);
+
+static const watch_face_t day_one_face = {
+    day_one_face_setup,
+    day_one_face_activate,
+    day_one_face_loop,
+    day_one_face_resign,
+    NULL
+};
+
+#endif // DAY_ONE_FACE_H_